A bacterial strain (designated as N4) of Pseudoxanthomonas was isolated from a denitrification biofilter reactor. This study examined its degradation capability of di(2-ethylhexyl) phthalate (DEHP) and its denitrification ability. All results showed that, strain N4 could use DEHP as a carbon and energy source. Strain N4 demonstrated good DEHP degradation ability over a broad pH and temperature range. The optimal temperature and pH for DEHP degradation were 32 degrees C and 6.0, respectively. The kinetics of DEHP degradation by strain N4 were exponential in nature. Strain N4 showed denitrification ability and could reduce nitrate and nitrite but not with DEHP as its carbon source. (C) 2014 Elsevier Ltd. All rights reserved.